This relates to a lay-in or suspended ceiling structure and to acoustic ceiling panels incorporated in the ceiling structure, the ceiling panels being of the type comprising a core having front and rear layers on its respective front and rear sides.
Lay-in ceiling structures typically comprise a system of panels installed on a metal grid. The grid is positioned to create a plenum, or air space, between the rear side of the panels and a fixed structural ceiling thereabove.
It has been heretofore proposed to provide ceiling panels with desirable acoustic characteristics by applying, to the front and rear sides of a core (or substrate), layers in the form of coatings and/or coverings of material (sometimes called skins) having sound-absorbing properties. Acoustic characteristics of such layer-core layer panels are typically determined by measuring the panel's overall resistance to airflow therethrough in the thickness direction of the panel.
The term “panel” as hereafter used, should be considered to mean a layer-core-layer type panel. As used herein, the expression lay-in or suspended ceiling structure means one in which a plenum or air space is formed between the acoustic panels and the rigid structural ceiling (typically about sixteen inches in height).
It has been generally considered that nearly optimum acoustic absorption (i.e., noise reduction coefficient (NRC) of at least 1.0) can be achieved if the panel is designed such that the overall airflow resistance of the panel in the thickness direction (height) of the panel is in the range of 1000-2000 MKS rayls.
However, room for improvement remains and it would be desirable to provide ways of optimizing preferably the class of ceiling panels comprising front and rear sides and a core, and in which the core does not provide the bulk of the airflow resistance for the entire panel.